Something really simple that I think encourages player cooperation is giving a small speed bonus while using a cart on a paved surface ( maybe like 5% ) to encourage the usage of roads for trading.
#Speed Bonus and Incentive for Roads.
mossy pike
urban sun
I think they have said that some pavement types do give a speed buff, but it doesn't say which ones
at the moment, it does seem like all pavement types at least make it so that running on them doesn't consume stamina
pastel smelt
to add onto this- they should make all pavement types give the same speed bonus but then also give higher tier vehicles an extra bonus on top of that while on pavement so that the onus of speed goes more to the individual player than the road type
because otherwise, all roads will look the same and it severely hampers people's ability to be creative with road designs